The present invention relates to a light curing device, especially for irradiating curable dental compositions, with a light source and a light guiding device, such as a light guide, having a light receiving opening, whereby in the path of the light beam between light source and light receiving opening a focusing lens is arranged. The device is especially used for curing dental plastic materials that are polymerizable under the effect of light.
Such a light curing device is known from German Offenlegungsschrift 32 37 510. In such a light curing device the light source is surrounded by a reflector which focuses the emitted light radiation onto a focusing lens. The plano-convex focusing lens, the planar surface of which is facing the light source, is designed to focus the light beam onto the light receiving opening of the light guide. In the known light curing device spectral lamps are used as light sources, which are relatively large and heavy in order to be able to introduce monochromatic light radiation into the light guide.
In order to facilitate handling of the device, the known light curing device has a flexible light guide of a length of 2 meters. With this construction, the operator is thus limited in his moveability by the connection via the light guide. Furthermore, with a comparatively long and flexible light guide there is always present the danger of kinking. Even though possible external damages cannot be seen, the resulting light efficiency of the light guide is considerably reduced without being apparent to the operator.
However, this carries the considerable risk that a light curing step is not completed so that the used dental material is not cured according to specification.
Furthermore, hand-held devices are known, for example, from German Offenlegungsschrift 42 11 230. With such hand-held devices it is conventional to use, for the comparatively compact arrangement, light sources of high energy density which results often in thermal problems. Despite the comparatively high energy expenditure, the light efficiency for these hand-held devices is still improvable.